3. 2020 Zigya Technology Labs Pvt. So light is the main factor, which influences transpiration. 13 min. These include: temperature; humidity; air movement; light intensity Low atmospheric pressure increases the rate of transpiration. Canopy structure. Stomata: the number of stomata per unit area affect the stomatal transpiration. Has a cooling effect on the leaf surface. © Factor # 1. Pressure - Increase in the pressure increase diffusion rate. This is largely because light stimulates the opening of the stomata . Continuity of protoplasm from one cell to another cell is through plasmodesmata. This reduced uptake of water slows down the rate of transpiration. Transpiration - Factors Affecting Rates of Transpiration PLANT PARAMETERS – These plant parameters help plants control rates of transpiration by serving as forms of resistance to water movement out of the plant. The lower the atmospheric pressure, the greater is the rate of evaporation of water from leaves. The cohesion and adhesion forces of the water molecules and the cell walls of the xylem vessels prevent the water column from disrupting. Required fields are marked *. Light also speeds up transpiration by warming the leaf. The root-shoot ratio, leaf surface area and surface area to volume ratio and leaf structure are the major internal factors affecting the rate of transpiration. So light is the main factor, which influence transpiration Cell membrane is not crossed. Temperature: With the increase of temperature water vapourises rapidly and increased the humidity in the atmosphere. Types of Transpiration. Transpiration is the loss of water from the plant surface into the atmosphere. 12 min. 6 min. The higher the number of stomata, the greater the rate of transpiration. Transpiration rate depends on the same factors which affect the evaporation rate. Guttation. STUDY. 10 min. Factors affecting the Transpiration Rate. The following points highlight the six main factors affecting transpiration in plants. The internal or plant factors affecting the rate of transpiration has been explained in this video. On the other hand, still air builds up a shell around the leaf reducing the steepness of vapour gradient. Both these factors increase the vapour gradient between sub-stomatal cavity and external atmosphere. Factors affecting the water potential are as followwing:i. Solute concentration - The dissolution of solute in water decreses its water potential. Factors affecting transpirationThe rate of transpiration depends on the following factors: External factors - i. Temperatureii. Wind speedInternal factorsi. ii) Rate of transpiration is directly proportional to the surface area of leaf. Internal factors. The environmental factors affecting the rate of transpiration are: Light, External or Environmental factors: 1. There are, however, a number of external factors that affect the rate of transpiration, namely: temperature, light intensity, humidity, and wind. Apoplast is the system of adjacent walls and continuous through the plant except at casparian strips. Water potential : This term was given by Slatyer and Taylor (1960). Internal water conditions. Humidity of Air: Distribution of stomata plays an important role in preventing loss of water vapour. In xerophytes cuticle is extremely thick and prevent transpiration through it. Temperature also helps opening of stomata since stomata remain open up to about 30° C. in fact, in the presence of light, the temperature has the greatest effect on the rate of transpiration. 4. There are different factors that can affect the rate of transpiration as discussed below. 2.Thickness of cuticle - Thick cuticle layer lowers the rate of transpiration. Briefly describe water potential. (A) Internal factors : 2. The water vapours diffuse through cucticle or through the stomata. 2. Describe internal factors affecting transpiration. The factors affecting rate of transpiration can be categorized under two groups: External or Environmental factors (eg. Leaf shape, thickness of cuticle and number and distribution of stomata influence the rate of transpiration. Sunken stomata help … Factors affecting transpiration. Moving air, especially the low speed wind, sweeps away the water vapour in the air outside the stomata, speeding up diffusion of water vapour by making a steeper gradient between stomatal cavity and the air. When the water potential of the soil water is lower than the cells of the root the permanent wilting, point has been reached and plants die quickly. The rate transpiration is affected by a number of environmental (external) and plant (internal) factors. Humidity of Air 2. 1. 4. Also light helps in increasing the temperature of atmosphere. The cellular factors affecting the rate of transpiration are: The orientation of leaf, The water status of the plant, Structural Peculiarities of the leaf, Total number and distribution of stomata in a leaf. Internal Affecting factors of transpiration. 2. Most alpine plants show xeromorphic features which help reduce water loss. It has been observed that rate of transpiration increases with increase in root shoot ratio Number of stomata - more the number of transpiration more will be the transpiration. 9 min. Surface area : More the surface area more will be the rate of diffusion. Leaf structure: The structural modification such as presence of thick cuticle, epidermal hairs, frequency of stomata, sunken stomata, developed palisade tissue etc. Water vapour pressure decreases as the atmospheric pressure decreases with increasing altitude. internal factors affecting the rate of transpiration - root to shoot ratio - surface area of leaves - stomatal frequency - structure of leaf. In most plants stomata open during the day. This is because of the fact that more stomatal openings are present on the under surface. The living epidemis and stomata are not required. Sign in. 5. Factors which affect transpiration rate both external and external are discussed here . Atmospheric Pressure 6. Water potential (Ψw) is expressed as the sum of solute potential (Ψs) and pressure potential (Ψp).Ψw = Ψs + Ψp. 1. v. Maintains the shape and structure of the plants cells by keeping them turgid. Notify me of follow-up comments by email. The factors affecting the transpiration include. are involved. 6 min. 9 min. Lightiv. It is denoted by Psi or Ψw and is expressed in Pascals (Pa). Transports minerals and nutrients to the plants.iv. external factors affecting plant growth Plant growth and development are influenced by physical, chemical and biological components in the plants environment. 1.Surface area of leaf - Leves having larger surface are have more transpiration. The external and internal factors that affect transpiration are as follows: External factors. Affecting factors of transpiration are of two types; External and Internal. 3. It is not aided by streaming movement of cytoplasm. Factors Affecting Transpiration - Internal. Transpiration in plants: types, mechanism, affecting factors and significance Define Transpiration and its significance? 4. For this reason transpiration takes place in daytime. Water status of the plantiv. Humidityiii. The internal factors that control the rate of transpiration are the leaf structure, root-shoot ratio, leaf area, age of plants. Factors affecting the rate of transpiration Many environmental factors, such as intensity of light, temperature, atmospheric humidity, wind, availability of soil water, etc., greatly affect the rate of transpiration. 1. Concentration gradient: The rate of diffusion is directly proportional to the concentration gradient. The water movement into the root cells by osmosis is reduced. On the other hand, in monocots, the leaves are vertical and stomata are distributed on both surfaces equally, thus the rate of transpiration is higher. The rate of transpiration is affected by several factors. Light : Light is very important factor of transpiration . Following factors affecting transpiration are external and internal factors like light air and temprature Advantages of Transpiration. atmospheric humidity, temperature, wind velocity, light, water supply, atmospheric pressure, sprays and dusts and vital activities) Deficiency of water in the plants will result in decrease of transpiration rate. It is independent of anatomy of leaf, stem and roots. how does temperature affect transpiration how does light intensity affect transpiration factors affecting transpiration ppt plant factors affecting transpiration Factor Effecting the Transpiration 9th Class Biology Chapter 9 Transport Online Videos Lecture. Your email address will not be published. It is a physiological process and occurs in plants. Differentiate between apoplast pathway and symplast pathway. The humidity of the atmosphere the gradient the sub-stomatal cavity and air outside the leaf. Factors affecting transpiration. 5. The root-shoot ratio, leaf surface area and surface area to volume ratio and leaf structure are the major internal factors affecting the rate of transpiration. The factors are: 1. More permeable the mebrane more will be the diffusion. It is aided by streaming movements of cytoplasm. what does rate of transpiration refer to. 4. Stomata tend to be open in the light, therefore, the rate of transpiration increases in the light than in the dark. Differences between Transpiration and Guttation. It is the difference in free energy or chemical potential per unit molal volume of water in a solution over its pure state at same temperature and pressure. X. The factors affecting the rate of transpiration can be categorized into two groups: (A) External or Environmental Factors and (B) Internal or Structural or Plant Factors. Creates transpiration pull for the absorption and the transport of water in plants.ii. High winds may result in closure of stomata. The Environmental Factors Affecting Transpiration In general, plants transpire fastest under the following climatic conditions: (a) bright day, (b) dry air, (c) moist soil, (d) warm temperature, and (e) windy day. Environmental factors that affect the rate of transpiration. 3. Any factor in the plants’ environment that is less than optimum, whether it is deficient or in excess, will limit plant growth (17). Environmental Factors. https://www.zigya.com/share/QklFTjExMDA3MTg4. The list below gives the factors which affect the transpiration rate. Several structural features of plants like leaf area, structure of leaf and its orientation, root-shoot ratio, age of the plant, etc. Atmospheric Humidity: The rate of transpiration is roughly inversely proportional to atmospheric humidity. Transpiration of a plant increases with its total leaf surface area and with leaf surface area to volume ratio. Rate of transpire varies greatly geographically and over time. External factors: (i) Light: Light regulates the transpiration directly and indirectly by two ways. It is the system of interconnected protoplasts. Structural features In plants, the water is lost in the form of water vapour from the stomata of the leaves. influence the rate of transpiration. Internal factors Root - Shoot Ratio : Transpiration shows a direct relation with the amount of water absorbed by the roots and the water lost through leaves. 1. In dark stomata are closed and stomatal transpiration is checked. There are a lot of internal and external factors which affect the rate of transpiration in plants which is as follows: External factors: External factors affecting transpiration - Light, atmospheric moisture, wind velocity, air temperature, solar radiation and soil environment. During daytime, the water lost through transpiration (by the leaves to the surroundings) causes the guard cells and other epidermal cells to become flaccid. 1. Temperature : The rate of diffusion is directly proportional to the temperature. (a) External Factors: Light: Photosynthesis takes place in presence of light and as a result stoma opens. supplies water for photosynthesis.iii. Low humidity outside the leaf favors transpiration because it increases the gradient. Water content of the leaves; Learn with Videos. Factors affecting the rate of transpiration : Intensity of light, temperature, atmospheric humidity, wind velocity, availability of soil water, etc. Storage of water in the soil leads to wilting of plants and closure of the stomata. The opening and closing of stomata. 3. More the solute more negative will be the water potential.ii. Soil Factors. 2. 2.Thickness of cuticle - Thick cuticle layer lowers the rate of transpiration. Different environmental conditions trigger both the opening and closing of stomata. These factors also affect the stomatal movements. This is called the cohesion-tension model of water transport. Download the PDF Question Papers Free for off line practice and view the Solutions online. The higher the temperature the greater the rate of transpiration since high temperature provides latent heat of vaporization and lowers the relative humidity of air. 6. Light affects transpiration indirectly. 232, Block C-3, Janakpuri, New Delhi, Cuticle: if the cuticle is thin the rate of transpiration is higher, for example in ferns 30%-45% water loss is cuticular since the cuticle is thin. Sunken stomata - lowers the rate of transpiration. Example Definitions Formulaes. Temperature 4. Light or Illumina­tion 3. Movement of Water Through Leaves. 2. Various forces such as vapour pressure, diffusion pressure, osmotic pressure, etc. As the film of water is continuous over the cells, thus a transpirational pull is generated by the loss of water from the stomatal pores of leaves. Ltd. Download books and chapters from book store. Any liquid can evaporate. Type # A. Number of stomata - more the number of transpiration more will be the transpiration. Increase rate of transpiration containing for longer periods often create internal water deficit in plants because absorption of water does not keep pace with it. Leaf Surface Area & Surface Area to Volume Ratio. Temperature. Internal Factors:-i) Rate of transpiration is directly affected by the thickness of cuticle covering on leaf surface. Factors Affecting Transpiration - External. Permeability of the membrane separating the solutions. is termed as transpiration. 3. Light Plants transpire more rapidly in the light than in the dark. Water vapour from transpiring surfaces rapidly moves into the atmosphere which is at low pressure. 9.1 Factors affecting the rate of transpiration. PLAY. External Factors: Light: Photosynthesis takes place in presence of light and as a result stomataopens. What are the factors affecting it ? the amount of water lost from a plant per unit time. 1. It is very essential for transpiration. Pressure - If pressure greater than the atmospheric pressure is aaplied to a pure water or solution, its water potential increases. Thus, windy conditions lead to an increased rate of transpiration. Related Questions to study. In dicots, the stomata are confined to lower epidermis usually, therefore not in, contact with environment directly and the rate of transpiration is lesser. If rate of transpiration exceeds rate of absorption, a water stress condition develops and rate of transpiration is reduced. In most plants stomata open during the day. Factors affecting Transpiration : Affecting factors of transpiration are of two types; External and Internal. 6. Percent of open stomataiii. 5. more will be the thickness less will be the transpiration. The loss of water in the form of vapor from the living tissues of aerial parts of plant such as leaf, stem, leaves etc. Wind 5. For example, the rate of transpiration is higher in Sorghum as compared to Corn since, it possesses secondary roots which increase its absorption surface. B. Sunken stomata - lowers the rate of transpiration. can reduce the rate of … It occurs through cell wall and intercellular spaces. It is a physical process and occurs on any free surface. Internal factors affecting transpiration : 1.Surface area of leaf - Leves having larger surface are have more transpiration. This creates a negative pressure or tension in the xylem vessels, from the surfaces of the leaves to the tips of the roots, through the stem. 2. Transpiration is useful to the plants in the following way:i. Factors affecting Transpiration Rate of Transpiration is affected both by the Internal and External Factors. As a result, the water present in the xylem is pulled as a single column from the stem. More transpiration process occurs from the lower surface of a dorsiventral leaf as compared to upper surface. The transpiration regulatory factors are of two types: External factors and Internal factors.. For example, conifers, the leaves are reduced to needles and the rate of transpiration is reduced, while the shade plants with large leaf surface area lose much water vapour. In xerophytes, the number of stomata are reduced and sunken, thus the rate of transpiration is lesser. 1. They, in turn, take water from the xylem. It can occur from both living and non-living surfaces. An increase in the air temperature warms the water inside the leaves more quickly causing it to evaporate quicker. The efficiency of absorbing (roots) and evaporating surfaces (shoots) affect the rate of transpiration. TThe water potential of pure water is always taken as zero at standard temperature and pressure. All mixtures have a water potential less than zero. It is dependent upon anatomy of root, stem and leaves. Root-Shoot Ratio The efficiency of absorbing (roots) and evaporating surfaces (shoots) affect the rate of transpiration. Rolling, twisting and curling of leaves also reduce transpiration because the amount of radiation received by the leaf is decreased. K+ ion and Sugar Concentration Theory. The number, size, position and the movement of stomata affect the rate of transpiration. The external and internal factors affecting the rate of transpiration are as follows: Revise with Concepts. Internal Factors. As the soil dries out the remaining soil water becomes more concentrated solution and becomes bound to soil particles more tightly. Delhi - 110058. Number and distribution of stomata,ii. The environmental factors such as humidity (vapour pressure), temperature, air movements (wind), atmospheric pressure, light and availability of soil water influence the rate of transpiration most. As the temperature increases the rate of diffusion increases. The osmotic potential increases and … Light: Light induces photosynthesis in guard cells leading to sugar synthesis. The rate of transpiration is directly proportional to leaf surface area and surface area to volume ratio. Intensity of sunlight; Temperature; Velocity of wind; Humidity; Carbon dioxide; Atmospheric pressure; Internal factors. (adsbygoogle = window.adsbygoogle || []).push({}); Factors Affecting the Rate of Transpiration, environmental factors that affect the rate of transpiration, how does light intensity affect transpiration, Chloroplast Structure and Function Detailed, Seed Dispersion And Seed dispersal methods. The various environmental factors affecting transpiration, particularly the rate of transpiration, are briefly discussed below. If the rate of transpiration exceeds the rate of absorption, the stomata get closed the cells lose their turgidity and the plant wilts. , still air builds up a shell around the leaf i. solute concentration - the dissolution of solute in decreses. Diffusion pressure, diffusion pressure, osmotic pressure, osmotic pressure, the water molecules and the movement of.! 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